The essence of a solid material can enter a liquid through a process known as infusion, wherein the solid material is placed into a liquid for a sufficient period of time and the essence passes from the solid material into the liquid. In a well known infusion process, the essence of coffee, including flavor, color and often caffeine enter heated water. It will be readily understood by those of ordinary skill in the art that caffeine is substantially not available to enter the liquid when the coffee has been decaffeinated. There are many conventional coffee makers that can be used to perform the process and include a percolator and drip type coffee maker. In such coffee makers, hot water is passed through the coffee grounds using gravity. A known quality of the coffee beverage is produced using such methods. In a percolator, the water is continuously heated and repeatedly passed through the grounds. In addition, coffee bags similar to conventional tea bags have also been introduced, wherein a filter bag of ground coffee is dipped into a hot cup of water using a string.
The coffee grounds are held together in each of a percolator, drip and bag infusion approach. In a conventional drip type coffee maker, ground coffee is held in a conical filter and appropriately sized filter housing. Hot water is poured into the ground coffee and passed once through the coffee grounds. In another well known process in an espresso machine, heated water and/or steam is forced through compressed coffee grounds to perform the infusion process.
Often, for dispensing of coffee drinks, a full pot of coffee is made and then maintained at a high temperature to be ready for dispensing to and consumption by a consumer. Unfortunately, the continual application of heat to prepared coffee can burn the coffee, thereby deteriorating its flavor and desirability. Also, coffee that is made and stored in an insulated thermal pot quickly degrades in its flavor. Though the precise mechanism for the degradation of the prepared and stored coffee is not well known, it is possible that the degradation occurs through a chemical reaction, such as by oxidation. In any case, it is generally recognized and accepted that freshly made coffee has superior flavor to ‘old’ coffee.
Tea, herbal tea, medications, chemical preparations and other liquids can also be produced using infusion. Tea bags are well known for infusing tea. However, some tea drinkers have long believed that loose teas provide a superior tea beverage to tea bags. One theory is that the hot water is provided free unrestricted access to all surfaces of the tea. This is especially true when the preparer stirs the loose tea in vessel while steeping the beverage. However, owing to the substantial convenience of tea bags relative to the clean-up problem associated with loose tea in the bottom of a pot, the use of tea bags is universally accepted and preferred. Though it will be recognized that infusion can take place for coffee, tea, herbs, medicines, or chemicals as well as other substances into water and/or other liquids, to avoid unnecessarily complicating the following discussion with extraneous detail, the remainder of this document will refer only to coffee, though other beverages and infusions are contemplated.
The press or so-called French Press is well known for making superior coffee infusions. FIG. 1 shows a conventional coffee press. A vessel 100 is provided for steeping the beverage. A measure of coffee grounds or tea 102 is provided in the vessel 100 along with hot water 104. The preparer can stir the hot water 104 during the infusion process to better promote the amount of infusion that takes place as desired. Once the desired extent of infusion is achieved, the preparer activates the press assembly 106 to slow or stop the infusion process.
To stop the infusion process, a conventional press assembly 106 is provided to confine the coffee grounds separate from the infused liquid coffee. The preparer depresses the press assembly 106 to the bottom of the vessel 100. This action traps the coffee grounds 102′ between the press assembly and the bottom of the vessel 100 (FIG. 2). Thereafter, the infused coffee beverage 104′ can be dispensed from the vessel 100 without any coffee grounds 102 or 102′ being present in the beverage to detract from the enjoyment of the beverage.
The press assembly 106 includes a filter screen 108. The filter screen 108 is configured to easily pass water but not coffee grounds. The conventional press assembly 106 includes a filter screen 108 which has openings sized to allow water or liquid to pass there through but to prevent coffee grounds from escaping above the filter into the beverage to be dispensed. Conventional filters in a French Press are formed of a pliant, flexible screen having small apertures to allow passage of the infused liquid. Conventionally, the filter screen 108 is slightly larger than the size of the opening of the vessel 100 to ensure that the filter screen 108 maintains positive and intimate contact with the interior surface of the vessel 100. Generally, the edges of the filter screen 108 are turned up. A pressing plate 110 is mounted over the filter screen 108. The pressing plate 110 includes a plurality of apertures to expose the filter screen 108 to the liquid. A coiled pressure spring 112 is circumferentially mounted to and around the exterior of the pressing plate 110 as well as adjacent and within the turned up edges of the filter screen 108. In this way, as is well known the pressure spring 112 applies outward pressure on the filter screen 108, to hold the filter screen 108 firmly against the inner wall of the vessel 100. This pressure prevents coffee grounds from escaping past the filter screen. Once the appropriate level of infusion has occurred, the user then depresses the press assembly using a plunger rod 114. Most press assemblies also include a vessel lid 116 and a rod end 118 for comfort to the user and also to prevent the lid from being removed from the rod 114.
For a conventional coffee press, it is important that the interior radius of the vessel be constant from its upper opening to its base. This allows the press assembly 106 to engage the inner wall of the vessel 100 from the top of the vessel 100 and throughout the traverse of the press assembly until it reaches the bottom of the vessel 100. As the press assembly 106 is pressed downwardly, the pressure of the liquid becomes greater under the filter screen 108. The increased pressure causes the infused liquid to pass through the filter screen leaving the coffee grounds 102 below the press assembly 106 and trapped against the bottom of the vessel 100. In the event that the radius of the vessel 100 is not constant and increases even momentarily causing a void between the press assembly 106 and the vessel 100, such as by a swelling of the vessel or owing to some other defect in a sidewall of the vessel 100, the pressurized liquid will seek to escape to the region above the press assembly 106 and pass rapidly through the void. Hence, in nearly every occurrence the void will cause coffee grounds to escape from below the press assembly 106 through the void. Generally, the liquid passing through the void forms a turbulent relatively high speed stream. Once this occurs, the user is unfortunately subjected to drinking coffee having undesirable coffee grounds contained therein. Drinking a coffee beverage that contains coffee grounds is unpleasant.
It is generally accepted that press made coffee and tea is superior to such beverages made by other techniques. However, in spite of the superior beverage made with a press, infusion presses have only gained limited acceptance. One reason for this limited acceptance is related to the difficulty and necessity surrounding cleaning the press. Upon completion of a pot of coffee made from a press, the press element must be removed from the vessel. Then, the grounds must be removed from the vessel. The removal of the grounds is a messy operation generally resulting in substantial grounds going down the drain.
Others have developed single serving sized press cups. These cups are sized to allow a user to prepare a single serving of press beverage. Unfortunately, as will be explained in more detail below, because the radius of the cup must be constant from its top opening to the bottom, the single serving sized press cups are made of glass, plastic or porcelain and hence are not economically disposable. This makes such cups unsuitable for several reasons. First, the cup and press assembly must be thoroughly cleaned to remove the trapped grounds after each cup is prepared and dispensed. The process of cleaning a press vessel is cumbersome in that it requires the press assembly to be withdrawn and then the coffee grounds to be removed before the washing process. Care must generally be taken to avoid allowing the grounds to pass into a sink or drain. Too many coffee grounds in the drain can cause the sink or drain to clog. Second, because such single sized press cups are not disposable, users cannot purchase a ‘to go’ cup of pressed coffee. This is unfortunate because pressed coffee is generally considered to be vastly superior in flavor to brewed or dripped coffee, even ‘on the go.’
For many applications involving dispensing of drinks, especially for the vending of drinks in a disposable cup, it is desirable that each of the cups 300 have a wider radius at their opening than at their bottom as shown in FIG. 3. Generally the dimension of the radius of each cup 300 varies linearly and decreases from the opening to the bottom. Such cups 300 have the shape defined in mathematics as a right circular conical frustum. This conical frustum shape allows users to nest the cups together in convenient stacks in the usual way as schematically shown in FIG. 3. The cups in FIG. 3 generally show a commonly available paper cup found in many coffee restaurants. Each of these cups 300 is formed of a paper side wall 302. The sidewalls are formed into a conical shape and adhesively seamed. A lip 304 is formed at the top of the cup 300 by a rolled rim of the same paper used to form the sidewalls 302. As is known, the lip 304 can be partially rolled or formed into a small tube. A bottom 308 is adhesively attached into each paper cup 300. The cup in FIG. 3 is representative only. It is well known that a variety of cup configurations are commercially available which generally have a conical frustum shape.
As is well known, the use of nesting allows a large number of cups to be stored in a relatively small space. Were it not for the ability to nest cups in this way, it would be impractical for drink vendors which use disposable cups to economically maintain a sufficient inventory of cups on hand in an small location.
It is readily apparent that a conventional press assembly cannot be used with a conical frustum cup because of the varying radius of the cup. If the press assembly 106 was appropriately sized to fit the radius of the cup near the bottom, the press assembly 106 would not make contact with the interior of the cup at the upper region thereby failing to keep the coffee grounds below the press assembly 106. Likewise, if the press assembly was appropriately sized to fit the radius of the cup near the opening at the top of the cup 300, it would be unable to be pressed to the bottom of the cup 300. If the press assembly is unable to reach to the bottom of the cup, the beverage is unavailable for consumption by the user. Either situation is unacceptable. Owing to at least these failures, no one heretofore has introduced a press assembly for single sized disposable conical frustum cup.
What is needed is a press assembly that can be used in a cup or vessel that has a radius which varies in size. What is further needed is a press assembly that can be used in a cup that has a radius that decreases linearly from the upper opening to the bottom of the cup. Further, a press assembly is needed for use in a conical frustum cup which is readily disposable.